Medicines and drugs. Analgesics. What is an analgesic? How do you feel pain ? What does “physical dependence” mean? What does ‘tolerance’ mean in this context?. Analgesics – reduce pain. Mild analgesics.
Mild analgesics, such as aspirin and paracetamol, function by stopping the transmission of pain from source to brain as they intercept the pain stimulus at the source.
They do this by interfering with the production of substances, such as prostaglandins, that are produced by injured tissues and that cause pain, swelling or fever.
Consider the relative value of these two approaches to pain management
A derivative = a new compound from changing another compound
To convert salicylic acid (2-hydroxybenzoic acid) into aspirin the hydrogen atom of the OH group is replaced by a COCH3 group to form an ester functional group which made the compound less irritating to the stomach and easier to take.